Optimising the Design and Implementaton of NDT Inspection for New Nuclear Power Plants.
The construction of new nuclear NPPs will place tremendous strain on the NDT service sector. The limited market that has existed since the last generation of plants were completed in the period from 1970 to 1990 has discouraged investment in technology and skilled personnel, while at the same time the expectations of plant operators and regulators have increased considerably as lessons have been learned from the operation of those plants. As a result of this the industry will find it very challenging to meet the demands for high quality, reliable inspection for the many plants that are scheduled or planned for construction in the next 15 years as nuclear new build undergoes a renaissance in response to global warming and energy security concerns.
The scale of the challenge is such that the industry will have to find ways of optimising inspection design to increase speed of application and reliability, while at the same time de-skilling the inspection process so that the available skilled personnel can be used more efficiently.
This study examined the feasibility of combining exisitng inspection design and modelling tools to design and validate advanced NDT inspection techniques incorporating automated defect recognition.
The tools and methodology were tested on a real-life challenge - the inspection of the AP1000 containment vessel. This has some 3.7km of welds requiring site radiography under ASME III code requirements, a process which will be a logistical challenge to the building programme. A UT alternative to the specifed RT inspection was designed and validated using computer modelling and verified by direct comparison with the performance of RT inspections on a representative test specimen.